I don't know about others but it is dependent on what times the client(s) want to work. Seems at times like our mastering facility is 24/7. Most days for me start at 5:30 am and end about 10 pm at night but that is because I have my mastering studio as part of my house and it is hard to get away from work. Yesterday I did a mastering session that started at 12 noon and ended at 6 pm. The day before I did an NPR show in the afternoon and a was repairing some equipment in the morning and the evening. Today I have a mastering session starting at 1:00 pm and this morning I have to go pick up a replacement printer for our office at a site 20 miles from our studio. The time to work varies a lot. Some studios run around the clock some work a "normal 9 to 6 pm schedule. It depends on the owner, the clientel and the work demands. You have to, as my father use to say, "make hay while the sun shines" or "if there is work coming in the door then get it done because you never know when it will stop"

The longest day I have had was 13 hours strait without a break. The all night session are the hardest and one client came in at 10 and we had breakfast at McDs the next morning after working the whole night.

It really all depends on the studio and how many other engineers are working there.
A lot of engineers like myself are freelance engineers, we don't necessarly work in just one studio..I go where my clients will be served best based on budget and requirements. That being said a freelance engineer can work anywhere from 20-70 or more hours a week.
A "house" engineer in a studio will work from 20-50 hrs a week depending on how busy the studio is and how many other engineers work there, but these day's there's so many owner/operator studios and freelance engineers that it's hard for a person to work in one studio...

The main thing about recording and recording studios is that nothing is really typical. You spend the hours to do what needs to be done based on the client and your ability to able to serve their needs. What is typical is that the more money you make off the project and/or the more you enjoy working on the project has much more to do with the amount and length of hours you put into a typical day for that specific project. If you own or are a freelance engineer paid by salary or per project, you are very likely to work many more hours per day and per week then an employee who is not salary and subject to labor laws.

My maximum has been during my assisntant days as a straight 23 hours...

Now operating my own studio I try to get the work when it comes, and some clients of mine only have time to work in week ends or at night, but it's not the rule, as I almost always work during the day; my "scheduled" hours are 9 am to 8 pm, with enough flexibility to go one hour or more if sometimes a session lasts longer (and it happens often); sometimes I have a 12 hours day, sometimes 6.
I wonder how those "round the clock" engineers or producers deal with their private life or family, we all know that this isn't a typical 9 to 5 job, but I think you have to choose whether you have a private life or if this work is your life.

The longest run I've had was 36 or so hours with a couple of hours for a nap...

I assisted a 12 hour session which was a 13 hour session for me because I was there before and after, then after that I engineered a session untill about 7 or so AM, then napped till 9:00...then got up for that day's 12 hour session which I was assisting.

It was hard but I made it through it. I'll never do it again though...that's just too much and I don't like working when I'm not at my best..

As a mixer, the longest I stayed in the studio was 7 days. I did not leave for 7 days. I ate at the console, took naps on the couch and showered in a nasty basement of the building. At one point I fell asleep on the console while riding some faders. woke up and the tape machine was still looping the song. the longest without sleep was 50 hours as an assistant. funny assistant story actually. The client was mixing an entire album over 3 days, we just got the first panasonic dat machine and I was playing around with it during the session and decided to record the mixes to dat as well as the half inch so I could compare them later and see how this new format sounded. anyway, we were printing to these oversized 14 inch reels of half inch and all we had were 12" takeup reels. somewhere around the 36 hour mark, i'm spooling mixes onto different reels and the tape is winding and I look down and i'm spooling a 14 inch reel to a 12 inch reel and wasn't paying attention and noticed that the tape had wound about 1 1/2"'s beyond the edge of the 12" reel. I hit stop on the machine, the tape dropped and wrapped around the hub and mangled a few songs then snapped. the client didn't notice that this had happened and were still mixing away. it was so badly mangled that the only thing I could do was take a razor blade and start cutting away tape. Assesed the damage and realized that 3 songs were gone. I convined the engineer that he should get some sleep cause he looked like hell and they agreed to take a break for 4 hours. they left and I remembered that I was recording the mixes to dat and decided to dump the mixes from dat to some new half inch. Never told the client. they came back after 4 hours as I was cleaning up and we finished the album.

As a mixer, the longest I stayed in the studio was 7 days. I did not leave for 7 days. I ate at the console, took naps on the couch and showered in a nasty basement of the building. At one point I fell asleep on the console while riding some faders. woke up and the tape machine was still looping the song. the longest without sleep was 50 hours as an assistant. funny assistant story actually. The client was mixing an entire album over 3 days, we just got the first panasonic dat machine and I was playing around with it during the session and decided to record the mixes to dat as well as the half inch so I could compare them later and see how this new format sounded. anyway, we were printing to these oversized 14 inch reels of half inch and all we had were 12" takeup reels. somewhere around the 36 hour mark, i'm spooling mixes onto different reels and the tape is winding and I look down and i'm spooling a 14 inch reel to a 12 inch reel and wasn't paying attention and noticed that the tape had wound about 1 1/2"'s beyond the edge of the 12" reel. I hit stop on the machine, the tape dropped and wrapped around the hub and mangled a few songs then snapped. the client didn't notice that this had happened and were still mixing away. it was so badly mangled that the only thing I could do was take a razor blade and start cutting away tape. Assesed the damage and realized that 3 songs were gone. I convined the engineer that he should get some sleep cause he looked like hell and they agreed to take a break for 4 hours. they left and I remembered that I was recording the mixes to dat and decided to dump the mixes from dat to some new half inch. Never told the client. they came back after 4 hours as I was cleaning up and we finished the album.

Click to expand...

now that was a close call.....
i remember mixing this country artist back in the eighties. we had a scully multitrack. as i was rewinding the tape the brakes decided to kick in and the tape snapped. the client actually started to cry. i felt so bad but it was no one's fault. luckily it snapped in the chorus of the song. we rolled in another 24 track bounced another chorus over and spliced it in. it all worked out fine in the end but what a nightmare....... the old days of really cut and pasting, god i miss them.